http://scp-sandbox-3.wikidot.com/crazed-ideas
hopefully, this is an interesting SCP, I've tried to create one that could be classed Euclid/keter, also one that would require an entire site built around it, also designing the site to become a fully functional site that is incredibly expansive. I have been working on this for the past week now on and off.
I would appreciate any critiques or ideas about how I could improve this.

Please don't put sandbox links in the thread summary; that messes with the display on some mobile devices. Also, links in the thread summary aren't always clickable. ~Zyn

Okay, I took a quick look at this—and to be honest author, this will need a lot of work if you want it to stand a chance on the mainsite. From a quick 10-second glance, there's a lot that makes me as a reader wary of the quality of the article:

You still have "(indicate which class)" placeholder text in the object class section.

Unnecessary brackets in the containment section.

Lack of proper paragraph spacing. Please put a line space between separate paragraphs.

Unnecessary capitalization in the middle of sentences.

Lack of proper spacing after colons.

Unnecessary words in "scare quotes"—in-universe, the article is written by a professional who knows the correct terminology to use, and wouldn't need to approximate.

Excessively specific measurements. If your meters measurement is to the second decimal, might as well use centimeters, though if the thing is Keter, one wonders how the Foundation managed to obtain such a specific number.

Confusion of "effects" and "affects".

Run-on, jumbled, or generally confusing to parse sentences like, "Due to one of the anomalous affects it has on the surrounding area it is unknown as to how long it has existed at this location as any persons coming within the area deviate from the boundary and leave with no memory of its interaction, this has proven to not affect those who are aware of its existence."

And so on. There's a lot more, but these are what I saw in the first 10 seconds or so of skimming.

Overall, this is just a stereotypical overpowered humanoid thing, and the focus on shadows and darkness kind of bring to mind way too many edgy OC-types that have been attempted and done poorly in the past. Same goes for the compulsive effects; we have a lot of SCPs tagged with "compulsion" that force people to act a specific way. Furthermore, an SCP's effect forcing someone to do something tends to be a bit of a lame narrative, since things are more interesting if there's a struggle involved, and/or if the people instead do terrible things of their own volition. Consider reading through the further discussion on the narrative issues of compulsion and addiction effects.

Right now, you seem to have invested a lot of thought into the small details and hyping up how dangerous the thing is, while not addressing the fact that the humanoid is fundamentally kind of bland because it follows such a typical and commonly seen formula.